In geometry, a translation is the shifting of a figure from one place to another without rotating, reflecting or changing its size. This is done by moving the vertices of the figure the prescribed number of spaces on a coordinate plane and then drawing the new figure.
These PFDs are designed to keep the wearer in a vertical position, but it is the wearersâ responsibility to maneuver themselves into a face-up position. Type III PFDs will keep unconscious wearers face-up just as well as a Type II vest.
What kind of PFD do I need? PFDs are categorized by Type, i.e. Type I, II, III, IV or V. Types I, II and III are commonly worn by recreational boaters, while Type IVs are throwable devices such as life rings and buoyant cushions. Type Vs are for special uses, as will be discussed later.